dccp_send.c

   1 /*
   2  * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file dccp_send.c paraslash's dccp sender */
   8
   9 /*
  10  * based on server.c of dccp-cs-0.01.tar.bz2,
  11  * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
  12  */
  13
  14 #include <sys/types.h>
  15 #include <dirent.h>
  16
  17 #include "para.h"
  18 #include "error.h"
  19 #include "string.h"
  20 #include "afh.h"
  21 #include "afs.h"
  22 #include "server.h"
  23 #include "net.h"
  24 #include "list.h"
  25 #include "vss.h"
  26 #include "send.h"
  27 #include "dccp.h"
  28 #include "fd.h"
  29 #include "close_on_fork.h"
  30 #include "chunk_queue.h"
  31 #include "server.cmdline.h"
  32
  33 /** the list of connected clients **/
  34 static struct list_head clients;
  35 static int listen_fd = -1;
  36 static struct sender *self;
  37
  38 /** Maximal number of bytes in a chunk queue. */
  39 #define DCCP_MAX_PENDING_BYTES 40000
  40
  41 /** describes one connected client */
  42 struct dccp_client {
  43         /** the dccp socket */
  44         int fd;
  45         /** address information about the client */
  46         struct sockaddr_in addr;
  47         /** the position of this client in the client list */
  48         struct list_head node;
  49         /** non-zero if audio file header has been sent */
  50         int header_sent;
  51         /** The list of pending chunks for this client. */
  52         struct chunk_queue *cq;
  53 };
  54
  55 static void dccp_pre_select( int *max_fileno, fd_set *rfds,
  56                 __a_unused fd_set *wfds)
  57 {
  58         if (listen_fd < 0)
  59                 return;
  60         FD_SET(listen_fd, rfds);
  61         *max_fileno = PARA_MAX(*max_fileno, listen_fd);
  62 }
  63
  64 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  65 {
  66         struct dccp_client *dc;
  67         int ret;
  68
  69         if (!FD_ISSET(listen_fd, rfds))
  70                 return;
  71         dc = para_calloc(sizeof(struct dccp_client));
  72         ret = para_accept(listen_fd, &dc->addr, sizeof(struct sockaddr_in));
  73         if (ret < 0) {
  74                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
  75                 return;
  76         }
  77         PARA_NOTICE_LOG("connection from %s\n", inet_ntoa(dc->addr.sin_addr));
  78         dc->fd = ret;
  79         para_list_add(&dc->node, &clients);
  80         add_close_on_fork_list(dc->fd);
  81         mark_fd_nonblock(dc->fd);
  82         dc->cq = cq_new(DCCP_MAX_PENDING_BYTES);
  83 }
  84
  85 static int dccp_open(void)
  86 {
  87         struct sockaddr_in servaddr;
  88         int ret;
  89
  90         ret = dccp_get_socket();
  91         if (ret < 0)
  92                 return ret;
  93         listen_fd = ret;
  94
  95         memset(&servaddr, 0, sizeof(servaddr));
  96         servaddr.sin_family = AF_INET;
  97         servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  98         servaddr.sin_port = htons(conf.dccp_port_arg);
  99         ret = bind(listen_fd, (struct sockaddr *)&servaddr, sizeof(servaddr));
 100         if (ret < 0)
 101                 return -E_DCCP_BIND;
 102         ret = dccp_set_socket(listen_fd);
 103         if (ret < 0)
 104                 return ret;
 105         ret = listen(listen_fd, 0);
 106         if (ret < 0) {
 107                 PARA_ERROR_LOG("%s\n", strerror(errno));
 108                 return -E_DCCP_LISTEN;
 109         }
 110         PARA_DEBUG_LOG("listening on fd %d\n", listen_fd);
 111         add_close_on_fork_list(listen_fd);
 112         mark_fd_nonblock(listen_fd);
 113         return 1;
 114 }
 115
 116 static void dccp_shutdown_client(struct dccp_client *dc)
 117 {
 118         PARA_DEBUG_LOG("shutting down %s (fd %d)\n", inet_ntoa(dc->addr.sin_addr),
 119                 dc->fd);
 120         close(dc->fd);
 121         del_close_on_fork_list(dc->fd);
 122         cq_destroy(dc->cq);
 123         list_del(&dc->node);
 124         free(dc);
 125 }
 126
 127 /*
 128  * ret: Negative on errors, zero if nothing was written and write returned
 129  * EAGAIN, number of bytes written else.
 130  */
 131 static int dccp_write(int fd, const char *buf, size_t len)
 132 {
 133         size_t written = 0;
 134         int ret = 0;
 135
 136         while (written < len) {
 137                 ret = write(fd, buf + written, PARA_MIN(1024, len - written));
 138                 /*
 139                  * Error handling: CCID3 has a sending wait queue which fills up and is
 140                  * emptied asynchronously. The EAGAIN case means that there is currently
 141                  * no space in the wait queue, but this can change at any moment and is
 142                  * thus not an error condition.
 143                  */
 144                 if (ret < 0 && errno == EAGAIN)
 145                         return written;
 146                 if (ret < 0) {
 147                         PARA_ERROR_LOG("%s\n", strerror(errno));
 148                         return -E_DCCP_WRITE;
 149                 }
 150                 written += ret;
 151         }
 152         return written;
 153 }
 154
 155 static int queue_chunk_or_shutdown(struct dccp_client *dc, long unsigned chunk_num,
 156         size_t sent)
 157 {
 158         int ret = cq_enqueue(dc->cq, chunk_num, sent);
 159         if (ret < 0) {
 160                 PARA_NOTICE_LOG("enqueue error\n");
 161                 dccp_shutdown_client(dc);
 162         }
 163         return ret;
 164 }
 165
 166 static int send_queued_chunks(struct dccp_client *dc)
 167 {
 168         struct queued_chunk *qc;
 169         while ((qc = cq_peek(dc->cq))) {
 170                 char *buf;
 171                 size_t len;
 172                 int ret;
 173                 cq_get(qc, &buf, &len);
 174                 ret = dccp_write(dc->fd, buf, len);
 175                 if (ret < 0)
 176                         return ret;
 177                 cq_update(dc->cq, ret);
 178                 if (ret != len)
 179                         return 1;
 180                 cq_dequeue(dc->cq);
 181         }
 182         return 1;
 183 }
 184
 185 static void dccp_send(long unsigned current_chunk,
 186                 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
 187 {
 188         struct dccp_client *dc, *tmp;
 189         int ret;
 190         char *header_buf;
 191         size_t header_len;
 192
 193         if (listen_fd < 0 || !len)
 194                 return;
 195
 196         list_for_each_entry_safe(dc, tmp, &clients, node) {
 197                 if (!dc->header_sent && current_chunk) {
 198                         header_buf = vss_get_header(&header_len);
 199                         if (header_buf && header_len > 0) {
 200                                 if (queue_chunk_or_shutdown(dc, -1U, 0) < 0)
 201                                         continue;
 202                         }
 203                         dc->header_sent = 1;
 204                 }
 205                 ret = send_queued_chunks(dc);
 206                 if (ret < 0) {
 207                         dccp_shutdown_client(dc);
 208                         continue;
 209                 }
 210 //              PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
 211                 ret = dccp_write(dc->fd, buf, len);
 212                 if (ret < 0) {
 213                         PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
 214                         dccp_shutdown_client(dc);
 215                         continue;
 216                 }
 217                 if (ret != len)
 218                         queue_chunk_or_shutdown(dc, current_chunk, ret);
 219         }
 220 }
 221
 222 static void dccp_shutdown_clients(void)
 223 {
 224         struct dccp_client *dc, *tmp;
 225
 226         list_for_each_entry_safe(dc, tmp, &clients, node)
 227                 dccp_shutdown_client(dc);
 228 }
 229
 230 static char *dccp_info(void)
 231 {
 232         static char *buf;
 233         int num_clients = 0;
 234         struct dccp_client *dc, *tmp;
 235
 236         free(buf);
 237         list_for_each_entry_safe(dc, tmp, &clients, node)
 238                 num_clients++;
 239         buf = make_message("dccp connected clients: %d\n", num_clients);
 240         return buf;
 241 }
 242
 243 static char *dccp_help(void)
 244 {
 245         return make_message("no help available\n");
 246 }
 247
 248 /**
 249  * the init function of the dccp sender
 250  *
 251  * \param s pointer to the dccp sender struct
 252  *
 253  * It initializes all function pointers of \a s and starts
 254  * listening on the given port.
 255  */
 256 void dccp_send_init(struct sender *s)
 257 {
 258         int ret;
 259
 260         INIT_LIST_HEAD(&clients);
 261         s->info = dccp_info;
 262         s->send = dccp_send;
 263         s->pre_select = dccp_pre_select;
 264         s->post_select = dccp_post_select;
 265         s->shutdown_clients = dccp_shutdown_clients;
 266         s->help = dccp_help;
 267         s->client_cmds[SENDER_ON] = NULL;
 268         s->client_cmds[SENDER_OFF] = NULL;
 269         s->client_cmds[SENDER_DENY] = NULL;
 270         s->client_cmds[SENDER_ALLOW] = NULL;
 271         s->client_cmds[SENDER_ADD] = NULL;
 272         s->client_cmds[SENDER_DELETE] = NULL;
 273         self = s;
 274         ret = dccp_open();
 275         if (ret < 0) {
 276                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 277                 s->status = SENDER_OFF;
 278         } else
 279                 s->status = SENDER_ON;
 280 }